Atari's huge multiplayer arcade
games from the 1970's are pretty hard to find. This page is about the
commonality (and otherwise) of the earlier machines, not the Sprint or
Tank series.

I own and have repaired a *lot*
of Indy stuff for others, so I thought i'd post my findings - mainly because
the pcbs are not intuitively labelled from the factory. Every Indy pcb
is etched with "Indy 800", no matter if its from the 4 or 8
player game, despite them being incompatible in most cases. Just identifying
them is usually the main hurdle. Secondly is then working out if you have
a full and correct set! I've been buying the individual pcbs from eBay
since the late 90's and have been able to put together a complete set
plus obtaining a cage, which have come from all over the place!

The
PCBs:

(technically this is
an Indy 4 cage with an extra 4 car pcbs in it :)

The heart of the game - Atari
developed the card rack for Indy 800 first then later stripped down the
existing set for just 4 players. The pcbs do turn up from time to time,
but rarely/never as a complete set, usually its just individual boards.
The PCB cage itself is very hard to find, whereas individual pcbs do turn
up randomly.

There are 5 different pcbs
in the rack as follows:

board

QTY Indy 800

QTY
Indy 4

Interchangeability
notes:

CAR

8

4

Same
in both games

SCORE

1

1

Unique

SYNC

1

1

If
you exchange 2 PROMs you can change these around.

COIN

1

1

Unique

PSU

1

1

*see
note

BACKPLANE(cage)

1

1

Same
in both games

*note : Indy 800 psu
can be used in Indy 4. Indy 4 psu can be used in Indy 800 but you will
only have four working coin mech lockout coils - only a slight inconvenience
but it will power it.

When i say 'Unique'
in the table above the meaning is that to convert an Indy 4 Score or Coin
pcb to work in Indy 800 there are a lot of chips required, clipped legs
and cut traces to re-instate and lots of blue patch wire to remove. Its
not impossible, but its a _lot_ of work and i would say barely worth it
unless you are completely stuck. Some later revisions of Indy 4 pcbs also
had these changes effected in the etching so conversion may be even more
of a nightmare.

Produced a year or so later,
a stripped-down version
- 4-players stand around a square cabinet, 2 players on 2 sides, with
2 blank sides.
- Players have gas, brake, steering wheel only
- Car Colours are Green, Cyan, Violet, Red

Telling
the PCBs apart!

Here's some side-by-side photos,
800 on the left, 4 on the right, never confuse the two again!

PCB

COIN

PSU

SCORE

SYNC

INDY 800
CAGE
(or PCB rack)

Not the best photo
but you can see that the rack has standard 19" rack mount flanges,
plus rounded top/bottom entry bars that fit the car ejector tool nicely.
The edge connectors are very stiff to insert/remove PCBs and hence then
eed for a card ejector tool.

INDY 4
CAGE
(or PCB rack)

Instead of 19"
rack flanges this has 'feet' flanges instead. Top and bottom crossbars
are set-back, PCB edge connectors are a lot more forgiving than indy
800, cards can be inserted and removed by hand.

Why do you find
more Indy 4 pcbs than Indy 800?

Page 5 of the Indy 4 manual
TM-055 tells us that each game actually shipped from the factory with
one spare pcb for each of the folowing: STEERING, CAR, COIN, SCORE, SYNC!

This probably saved the operator
a lot of hassle and correspondence back with Atari and downtime servicing
this beast if it failed. A bad machine taking up such floorspace rapidly
loses revenue! Looks like they didn't relise this until they shipped Indy
4 however. These spare pcbs do not appear to be noted as supplied with
an Indy 800 machine purchase.

Tech
Centre:

After working on
around 18 CAR pcbs in a row, I spotted a batch failure problem with Motorola
MLM309K regulators with date code 7616 - at least 4 were found bad, and
one failed under burn testing. I have other pcbs where this batch regulator
has not failed yet.. but its worth keeping an eye out for.

In
Summary:

So now, you should be able to
spot the PCBs apart, and work out what you need to collect a set.

If you have any spare pcbs for
this or any other 1970's Atari/Kee game PCBs to sell/trade then please let
me know as i'm always looking to expand my collection.

If you liked this
page, check out the rest
of my rambling mess of an ancient website, and maybe follow my page
on facebook for vintage videogame repairs and techie stuff :